Recording materials employing a manner of coloring by a reaction of a color forming dye and a developer have been widely used in thermal recording papers for recording outputted information from facsimiles, printers, etc. and pressure-sensitive copying papers for concurrently producing a plurality of copies, because such recording materials enable to record images in a short time by employing a relatively simple apparatus without requiring complex process such as development and fixation. As such recording materials, a material capable of instantly color forming, keeping whiteness of the part where no color is formed, hereinafter referred to as “background”, and providing high hardness of the color formed images is required. However, in view of stability during storing in long-term basis, a recording material capable of providing excellent lightfastness to the color formed images is particularly desired. In this concern, development of color forming dyes, developers, stabilizers during storing, etc. has been tried in the field of this industry, however, a material having excellent sensitivity in color forming, giving whiteness on the background and image stability with a good balance and an enough satisfaction has not been obtained.
As compounds that are related to the present invention, in Jap. Pat. Appln. KOKAI Publication Nos. 2-204091, 1-72891 and 4-217657, the phenol compounds are disclosed as examples for a developer. In these disclosures, however, a technique to provide a recording material having high performance in the background effect and image stabilizing effects is sought. In addition, compounds similar to the compounds of the present invention are disclosed in Jap. Pat. Appln. KOKAI Publication Nos. 62-10502 and 61-27955, however, the use of these compounds is directed to an agricultural chemical, and all these compounds do not contain hydroxy group in the molecule that is essential for a developer.